condition mean min max ZT0-3 1.335429 1.108748 1.56211 ZT4-7 0.880345 0.880345 0.880345 ZT8-11 0.75017 0.75017 0.75017 ZT12-15 0 0 0 ZT16-19 1.4135 1.4135 1.4135 ZT20-23 1.853545 1.853545 1.853545